DECREASE AND LONG-TERM RECOVERY OF CHOLINE-ACETYLTRANSFERASE IMMUNOREACTIVITY IN ADULT CAT SOMATOSENSORY CORTEX AFTER PERIPHERAL-NERVE TRANSECTIONS
DECREASE AND LONG-TERM RECOVERY OF CHOLINE-ACETYLTRANSFERASE IMMUNOREACTIVITY IN ADULT CAT SOMATOSENSORY CORTEX AFTER PERIPHERAL-NERVE TRANSECTIONS
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DOI：
10.1002/cne.903540302
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发表时间：
1995-04-10
影响因子：
2.5
通讯作者：
DESCARRIES, L
中科院分区：
文献类型：
--
作者：
AVENDANO, C;UMBRIACO, D;DESCARRIES, L
外周传入神经阻滞后大脑皮层的功能重组与许多神经递质和相关分子的变化有关。乙酰胆碱（ACh）增强神经元的反应性，并可能在活动依赖性皮层可塑性中发挥作用。在这项研究中，胆碱乙酰转移酶（ChAT）的免疫组织化学研究乙酰胆碱神经支配的初级躯体感觉皮层猫维持完全单侧前臂和爪去神经。研究了2-52周的存活时间。的deafferented对侧皮层的电生理学定义，和ChAT免疫反应纤维密度的定量估计，从前肢和后肢部门的区域3B在两个半球。在3b前肢扇区对侧的传入神经，ChAT阳性纤维的密度下降相对于同侧半球是明显的，在2周和最明显的13周，涉及所有的皮质层，除了第一层。有没有这样的减少在后肢部门，但损失的ChAT免疫反应延伸到部门代表近端前肢和躯干。ChAT免疫反应性的变化，不再发现后1年的生存。这种持久的，但可逆的降低ChAT免疫反应性可能会导致在基底神经元和/或营养的影响逆行施加皮质对这些细胞的传入活动的损失。减少乙酰胆碱的传输，然后可能会导致损失的γ-氨基丁酸（GABA）的抑制在去传入皮层通过减少抑制性中间神经元的激活。长期恢复正常的ChAT免疫反应在皮层可能是其功能重组的结果。(C)1995 Wiley-Liss，Inc.
The functional reorganization of cerebral cortex following peripheral deafferentation is associated with changes in a number of neurotransmitters and related molecules. Acetylcholine (ACh) enhances neuronal responsiveness and could play a role in activity-dependent cortical plasticity. In this study, choline acetyltransferase (ChAT) immunohistochemistry was used to investigate ACh innervation of the primary somatosensory cortex in cats sustaining complete unilateral forearm and paw denervations. Survival times of 2-52 weeks were examined. The deafferented contralateral cortex was defined electrophysiologically, and quantitative estimates of ChAT-immunoreactive fiber density were obtained from the forelimb and hindlimb sectors of area 3b in both hemispheres. In the 3b forelimb sector contralateral to the deafferentation, a decrease in density of ChAT-positive fibers relative to the ipsilateral hemisphere was apparent at 2 weeks and most pronounced at 13 weeks, involving all cortical layers except layer I. There was no such decrease in the hindlimb sector, but the loss of ChAT immunoreactivity extended to sectors representing proximal forelimb and trunk. Changes in ChAT immunoreactivity were no longer found after 1 year of survival. This long-lasting but reversible lowering of ChAT immunoreactivity could result from a loss of afferent activity in basalis neurons and/or trophic influences retrogradely exerted by cortex on these cells. Reduced ACh transmission might then contribute to the loss of gamma aminobutyric acid (GABA) inhibition in the deafferented cortex by decreasing the activation of inhibitory interneurons. The long-term recovery of a normal ChAT immunoreactivity in cortex could be a consequence of its functional reorganization. (C) 1995 Wiley-Liss, Inc.